Noorvik climate

Noorvik Frost Dates and Growing Season

NOAA 1991-2020 normals for Kotzebue Ralph Wein AP, 70 km from Noorvik, elevation 30 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Kotzebue Ralph Wein AP. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around June 5 and the first fall freeze around September 24, a growing season of about 110 days.

Median at 36°F
last June 15, first September 12
Median at 32°F
last June 5, first September 24
Median at 28°F
last May 27, first October 3

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FJul 1Jun 26Jun 21Jun 18Jun 15Jun 13Jun 10Jun 6Jun 2
32°FJun 17Jun 13Jun 10Jun 8Jun 5Jun 3Jun 1May 28May 20
28°FJun 7Jun 4Jun 2May 31May 27May 24May 20May 16May 12
24°FMay 30May 26May 22May 19May 16May 13May 11May 8May 4
20°FMay 24May 19May 16May 13May 10May 8May 5May 3May 1
16°FMay 18May 14May 11May 8May 6May 4May 2Apr 30Apr 25

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FAug 24Aug 29Sep 3Sep 8Sep 12Sep 15Sep 19Sep 22Sep 25
32°FSep 7Sep 14Sep 17Sep 21Sep 24Sep 26Sep 28Oct 1Oct 6
28°FSep 20Sep 24Sep 27Sep 30Oct 3Oct 6Oct 8Oct 11Oct 15
24°FSep 28Oct 2Oct 6Oct 9Oct 11Oct 13Oct 16Oct 18Oct 21
20°FOct 6Oct 9Oct 12Oct 15Oct 17Oct 19Oct 21Oct 23Oct 26
16°FOct 10Oct 14Oct 17Oct 20Oct 22Oct 24Oct 27Oct 29Nov 1

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F10710196928782777161
32°F1281211171141101061029787
28°F147141137132128125121116110
24°F162157153149145142138134128
20°F173168165162158155151147142
16°F184178174171168165161156151

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
14,907
Cooling degree days, base 65°F
5
Growing degree days, base 40°F
1,273
Growing degree days, base 45°F
759
Growing degree days, base 50°F
372
Growing degree days, base 55°F
137
Growing degree days, base 60°F
35

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January2,07500
February1,78100
March1,96700
April1,46100
May98703
June527268
July3043182
August3991104
September657015
October1,18100
November1,62700
December1,94100

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 70 km from Noorvik. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00026616 (Kotzebue Ralph Wein AP). Public domain.